Public transfers of food aid are intended largely to support vulnerable populations in times of stress. We use high frequency panel data among Ethiopian and Kenyan pastoralists to test the efficacy of food aid targeting under three different targeting modalities, food aid's responsiveness to different types of shocks, and its relationship to private transfers. We find that self-targeting food-for-work or indicator-targeted free food distribution more effectively reach the poor than does food aid distributed according to community-based targeting. Food aid flows do not respond significantly to either covariate, community-level income or asset shocks, nor to idiosyncratic, household-level income or asset shocks. Rather, food aid flows appear to respond mainly to more readily observable rainfall measures. Finally, food aid does not appear to affect private transfers in any meaningful way, either by crowding out private gifts to recipient households nor by stimulating increased gifts by food aid recipients.